/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.flink.table.dataview;

import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.ExecutionConfig;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.common.typeutils.TypeSerializer;
import org.apache.flink.api.common.typeutils.base.ListSerializer;
import org.apache.flink.table.api.dataview.ListView;

/**
 * Type information for {@link ListView}.
 *
 * @param <T> element type
 */
@Internal
public class ListViewTypeInfo<T> extends TypeInformation<ListView<T>> {

	private static final long serialVersionUID = 6468505781419989441L;

	private final TypeInformation<T> elementType;
	private boolean nullSerializer;

	public ListViewTypeInfo(TypeInformation<T> elementType, boolean nullSerializer) {
		this.elementType = elementType;
		this.nullSerializer = nullSerializer;
	}

	public ListViewTypeInfo(TypeInformation<T> elementType) {
		this(elementType, false);
	}

	public TypeInformation<T> getElementType() {
		return elementType;
	}

	public boolean isNullSerializer() {
		return nullSerializer;
	}

	public void setNullSerializer(boolean nullSerializer) {
		this.nullSerializer = nullSerializer;
	}

	@Override
	public boolean isBasicType() {
		return false;
	}

	@Override
	public boolean isTupleType() {
		return false;
	}

	@Override
	public int getArity() {
		return 1;
	}

	@Override
	public int getTotalFields() {
		return 1;
	}

	@SuppressWarnings("unchecked")
	@Override
	public Class<ListView<T>> getTypeClass() {
		return (Class<ListView<T>>) (Class<?>) ListView.class;
	}

	@Override
	public boolean isKeyType() {
		return false;
	}

	@SuppressWarnings("unchecked")
	@Override
	public TypeSerializer<ListView<T>> createSerializer(ExecutionConfig config) {
		if (nullSerializer) {
			return (TypeSerializer<ListView<T>>) (TypeSerializer<?>) NullSerializer.INSTANCE;
		} else {
			TypeSerializer<T> elementSerializer = elementType.createSerializer(config);
			return new ListViewSerializer<>(new ListSerializer<>(elementSerializer));
		}
	}

	@Override
	public String toString() {
		return "ListView<" + elementType + ">";
	}

	@Override
	public boolean equals(Object obj) {
		if (obj instanceof ListViewTypeInfo) {
			//noinspection unchecked
			ListViewTypeInfo<T> other = (ListViewTypeInfo<T>) obj;
			return elementType.equals(other.elementType) && nullSerializer == other.nullSerializer;
		}
		return false;
	}

	@Override
	public int hashCode() {
		return 31 * elementType.hashCode() + Boolean.hashCode(nullSerializer);
	}

	@Override
	public boolean canEqual(Object obj) {
		return obj != null && obj.getClass() == getClass();
	}
}
